Re: [PATCH] cheap lookup of symbol names on oops()

Cort Dougan
2002-07-25T17:25:22Z

I'm glad you found it useful.

I'm sorry, Aunt Tillie has a mind of her own about indentation. Patch
below with spaces turned to tabs.

I have the bk patch, if needed.

} Wow! very usefull patch. O want it for 2.4 and 2.5, please.
}
} But could you please fix up the indentation to match common kernel style?

diff -Nru a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
--- a/arch/i386/kernel/traps.c Thu Jul 25 11:19:18 2002
+++ b/arch/i386/kernel/traps.c Thu Jul 25 11:19:18 2002
@@ -201,8 +201,11 @@
esp = regs->esp;
ss = regs->xss & 0xffff;
}
- printk("CPU: %d\nEIP: %04x:[<%08lx>] %s\nEFLAGS: %08lx\n",
- smp_processor_id(), 0xffff & regs->xcs, regs->eip, print_tainted(), regs->eflags);
+ printk("CPU: %d\nEIP: %04x:[<%08lx>]",
+ smp_processor_id(), 0xffff & regs->xcs, regs->eip );
+ module_print_addr(" ", regs->eip, NULL);
+ printk(" %s\nEFLAGS: %08lx\n",
+ print_tainted(), regs->eflags);
printk("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
regs->eax, regs->ebx, regs->ecx, regs->edx);
printk("esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n",
diff -Nru a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c
--- a/arch/i386/mm/fault.c Thu Jul 25 11:19:18 2002
+++ b/arch/i386/mm/fault.c Thu Jul 25 11:19:18 2002
@@ -323,7 +323,9 @@
printk(KERN_ALERT "Unable to handle kernel paging request");
printk(" at virtual address %08lx\n",address);
printk(" printing eip:\n");
- printk("%08lx\n", regs->eip);
+ printk("%08lx", regs->eip);
+ module_print_addr(" ",regs->eip, NULL);
+ printk("\n");
asm("movl %%cr3,%0":"=r" (page));
page = ((unsigned long *) __va(page))[address >> 22];
printk(KERN_ALERT "*pde = %08lx\n", page);
diff -Nru a/arch/ppc/kernel/process.c b/arch/ppc/kernel/process.c
--- a/arch/ppc/kernel/process.c Thu Jul 25 11:19:18 2002
+++ b/arch/ppc/kernel/process.c Thu Jul 25 11:19:18 2002
@@ -245,8 +245,11 @@
{
int i;

- printk("NIP: %08lX XER: %08lX LR: %08lX SP: %08lX REGS: %p TRAP: %04lx %s\n",
- regs->nip, regs->xer, regs->link, regs->gpr[1], regs,regs->trap, print_tainted());
+ printk("NIP: %08lX");
+ module_print_addr(" ", regs->nip, NULL);
+ printk("\n");
+ printk("XER: %08lX LR: %08lX SP: %08lX REGS: %p TRAP: %04lx %s\n",
+ regs->xer, regs->link, regs->gpr[1], regs,regs->trap, print_tainted());
printk("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n",
regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0,
regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0,
diff -Nru a/include/linux/module.h b/include/linux/module.h
--- a/include/linux/module.h Thu Jul 25 11:19:18 2002
+++ b/include/linux/module.h Thu Jul 25 11:19:18 2002
@@ -411,4 +411,10 @@
#define SET_MODULE_OWNER(some_struct) do { } while (0)
#endif

+#ifdef CONFIG_MODULES
+void module_print_addr(char *, unsigned long, char *);
+#else /* CONFIG_MODULES */
+#define module_print_addr(x,y,z) do { } while (0)
+#endif /* CONFIG_MODULES */
+
#endif /* _LINUX_MODULE_H */
diff -Nru a/kernel/module.c b/kernel/module.c
--- a/kernel/module.c Thu Jul 25 11:19:18 2002
+++ b/kernel/module.c Thu Jul 25 11:19:18 2002
@@ -238,6 +238,63 @@
struct module *find_module(const char *name);
void free_module(struct module *, int tag_freed);

+/*
+ * Lookup an address in all modules (including the kernel) ksyms
+ * and print any corresponding symbol name. Useful for quick
+ * recognition of faulting addresses during panics without
+ * the need for user space tools.
+ * -- Cort <cort@fsmlabs.com>
+ */
+void module_print_addr(char *s1, unsigned long addr, char *s2)
+{
+ unsigned long best_match = 0; /* so far */
+ char best_match_string[60] = {0, }; /* so far */
+ struct module *mod;
+ struct module_symbol *sym;
+ int j;
+
+ /* user addresses - just print user and return -- Cort */
+ if ( addr < PAGE_OFFSET )
+ {
+ if ( s1 )
+ printk("%s", s1);
+ printk("(user)");
+ if ( s2 )
+ printk("%s", s2);
+ return;
+ }
+
+ for (mod = module_list; mod; mod = mod->next)
+ {
+ for ( j = 0, sym = mod->syms; j < mod->nsyms; ++j, ++sym)
+ {
+ /* is this a better match than what we've
+ * found so far? -- Cort */
+ if ( (sym->value < addr) &&
+ ((addr - sym->value) < (addr - best_match)) )
+ {
+ best_match = sym->value;
+ /* kernelmodule.name is "" so we
+ * have a special case -- Cort */
+ if ( mod->name[0] == 0 )
+ sprintf(best_match_string, "%s",
+ sym->name);
+ else
+ sprintf(best_match_string, "%s:%s",
+ sym->name, mod->name);
+ }
+ }
+ }
+
+ if ( best_match )
+ {
+ if ( s1 )
+ printk("%s", s1);
+ printk("(%s + 0x%lx)", best_match_string, addr - best_match);
+ if ( s2 )
+ printk("%s", s2);
+ }
+}

/*
* Called at boot time